Woodsia glabella

Smooth Woodsia

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Flora, fauna, earth, and sky...
The natural history of the northwoods

Name:

• Woodsia, for English botanist Joseph Woods (1776-1864).
• glabella, diminutive form of the Latin, glaber, "without hair, smooth, bald"
• Common name from the absence of the hairs so common in other Woodsia.
• Other common names include Smooth Cliff Fern, Woodsie Glabre (Qué), Dvärghällebräken (Swe), Dverglodnebregne (Nor), Dværg-Frynsebregne (Dan), Kaljukiviyrtti (Fin), Dvergliðfætla (Is), Kahler Wimperfarn (Ger)

Taxonomy:

• Kingdom Plantae, the Plants
  • Division Polypodiophyta, the True Ferns
    • Class Filicopsida
      • Order Polypodiales
        • Family Dryopteridaceae, the Wood Ferns
          • Genus Woodsia, the Cliff Ferns
• Taxonomic Serial Number: 17739

Description:

• A very small, loosely clustered fern, typically less than 6" tall.
• Fronds mostly basal, alternate, and compound.
  • Petiole (leafstalk) less than 1¼" long, segmented above the base at a swollen node; hairless and green or straw-colored over its full length; gooved on face; somewhat pliable and resistant to shattering.
  • Blade 1½"– 4" long (rarely to 6") and less than ½" wide, linear or lanceolate when mature, smooth on both sides with inconspicuous veining. Leaf margins crenate (small fronds, or approaching lobed, large fronds). Conspicuous hydathodes present (often as white slits to the veins, seen on the upper surface), or absent (not visible).
  • Rachis (axis) smooth and green
  • Pinnae (primary leaflets) fan-shaped toward base and wider than long, the lowest pairs widely spaced, opposite, and almost stemless; becoming ovate-lanceolate and longer than wide toward the tip, which is abruptly tapered to a rounded or broadly pointed end. The largest pinnae have 1-3 pairs of pear-shaped pinnules, smooth on both sides.
  • Pinnules (secondary leaflets) with smooth to crinkled edges without hairs. Vein tips slightly (if at all) enlarged, barely visible from above.
  • Sori small, with a distinct indusium; located very near edge of leaflet
  • Indusia of narrow hair-like segments, usually surpassing mature sporangia.
• Rootstalk quite small, at or below ground level; horizontal, compact, and stoloniferous, with cluster of persistent petiole bases of more or less equal length. Scales uniformly brown, lanceolate.
  • Roots fine, black, sparse, and hairlike.

Identification:

• Identifiable as Woodsia by
  • articulate bases to the petioles and the accumulation of petiole bases that have broken off below the articulation.
  • relatively small size for our area
  • affinity for rocky habitats
  • twice-cut fronds
• Distinguished from all other Woodsia in our area by its smooth stem and leaf surfaces, devoid of the hairs and scales so common in our other woodsias, as well as its smooth, yellow-green petiole (leaf stalk).
• Field Marks
  • absence of hairs and scales on fronds and leafstalks
  • presence of stem segmentation or articulation
  • color of mature leaf stalk

Distribution:

• Circumpolar, Alaska to Newfoundland and Greenland, south to Minnesota, New York, Vermont, New Hampshire, and Maine. Also northern Eurasia.
• At the southern limit of its range in northeastern Minnesota.

Habitat:

• Shaded cracks and ledges on cliffs; mostly calcareous rock, especially limestone
.

Fire:

Associates:

History:

Uses:

Reproduction:

• By spore

Propagation:

• By spore; difficult.

Cultivation:

• Hardy to USDA Zone 2 (average minimum annual temperature -50ºF)
• Generally not available commercially.

Links:

• Den Virtuella Floran, Naturhistoriska riksmuseet, Stockholm

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